mash: Migrate tray IME view to wm common types, move to //ash/common

ash/common/wm_shell.h

Index: ash/common/wm_shell.h
diff --git a/ash/common/wm_shell.h b/ash/common/wm_shell.h
index 5bfb905ff1f88845aa309f9e6075883053807a0a..59472a89b76f1b2995b842f328c1631c4256d325 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -145,6 +145,11 @@ class ASH_EXPORT WmShell {
   virtual void AddShellObserver(ShellObserver* observer) = 0;
   virtual void RemoveShellObserver(ShellObserver* observer) = 0;
 
+#if defined(OS_CHROMEOS)
+  // TODO(jamescook): Remove this when VirtualKeyboardController has been moved.
+  virtual void ToggleIgnoreExternalKeyboard() = 0;
+#endif
+
  protected:
   WmShell();
   virtual ~WmShell();